Marine Weather Net

Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal out 20 to 60 NM Marine Forecast


OVERNIGHT

NNW
WINDS
15 - 20
KNOTS

SUNDAY

N
WINDS
15
KNOTS

SUNDAY NIGHT

NNW
WINDS
10 - 15
KNOTS

MONDAY AND MONDAY NIGHT

NW
WINDS
5 - 10
KNOTS

The Marine Weather Forecast In Detail:
GMZ074 Forecast Issued: 1028 PM EST Sat Nov 16 2019

SMALL CRAFT ADVISORY IN EFFECT
Overnight...Northwest To North Winds 15 To 20 Knots. Seas 5 To 8 Feet. Isolated Showers.
Sunday...Northwest To North Winds Near 15 Knots. Seas 3 To 6 Feet. Isolated Showers.
Sunday Night...Northwest To North Winds 10 To 15 Knots. Seas 2 To 4 Feet. Isolated Showers.
Monday And Monday Night...Northwest Winds 5 To 10 Knots. Seas 2 To 3 Feet. Isolated Showers.
Tuesday...Northwest Winds 10 To 15 Knots. Seas Around 2 Feet. Isolated Showers.
Tuesday Night...North To Northeast Winds 10 To 15 Knots. Seas 2 To 3 Feet. Isolated Showers.
Wednesday...Northeast Winds Near 15 Knots. Seas 2 To 4 Feet. Isolated Showers.
Wednesday Night...Northeast To East Winds Near 15 Knots. Seas 3 To 5 Feet.
Thursday...Northeast To East Winds Near 15 Knots. Seas 3 To 5 Feet. Isolated Showers.
Thursday Night...Northeast To East Winds 10 To 15 Knots. Seas 3 To 4 Feet. Isolated Showers.
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Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005
1028 PM EST Sat Nov 16 2019

Deepening low pressure off the South Carolina coast late this evening will gradually lift out and exit to the northeast through Sunday night, leaving behind broad and weak high pressure centered over the western Gulf on Monday. The western Gulf high will strengthen and move to the northern Gulf Coast on Tuesday, across the Southeast U.S. on Wednesday, and emerge into the western Atlantic on Thursday.

Gulf Stream
The Approximate Shoreward Edge of the Gulf Stream as of November 16...
- 56 NM South of Dry Tortugas Light...on Loggerhead Key.
- 38 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 33 NM South of Sand Key Light...off Key West.
- 25 NM South of Looe Key...off Big Pine Key.
- 15 NM South of Sombrero Key Light...off Marathon. Less than
- 1 NM Southeast of Alligator Reef Light...off Islamorada.
- 1 NM Southeast of Molasses Reef Light...off Key Largo.
- 1 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion
National Weather Service Key West FL
1017pm EST Sat Nov 16 2019

Pleasant dry season weather prevails across the Keys on this Saturday evening. Radar shows no precipitation across the area. Infrared satellite imagery depicts Gulf stratcu moving over the Lower Keys at times, while clear skies prevail across the Middle and Upper Keys. Temperatures along the island chain range from mid 60s in the Upper Keys to the lower to mid 70s in the Lower Keys. These temperatures, combined with dewpoints in the lower 60s, and NNW breezes of 10 to 20 mph, are providing very comfortable outdoor conditions.

Surface analysis depicts the cold front which moved through the Keys early this morning now extending from a low off the Carolina coast through the central Bahamas and central Cuba into the western Caribbean. A large high pressure area behind the front sprawls from New England into the Gulf of Mexico. The 00Z Key West and Miami soundings found strong frontal inversions based between 4000 and 6000 feet, with PW values (Precipitable Water values) at or below one inch and near the 10th percentile for this time of year.

Overnight, area of stratocu will continue to stream across the Lower Keys, and cannot completely rule out a light shower or sprinkle, but the chances of any measurable precipitation are quite low. Elsewhere in the Middle and Upper Keys, expect mostly clear skies as they remain in the typical mainland shadow under post-frontal NNW flow. Lows by morning will drop to around 60 in the far Upper Keys, and should reach the mid 60s in the Middle Keys, but the longer flow trajectory over warm waters will prevent low temps in the Lower Keys from dropping below the upper 60s to near 70. A minor forecast update has been sent to reflect the above reasoning.

Marine
Evening observations show NW to N winds slowly decreasing across the western sections of the Keys coastal waters, while developing drainage flow off the mainland is holding winds steady over eastern sections. Expect fresh NNW breezes to persist overnight across most areas. Seas are still running a foot or two above guidance at the Pulley Ridge buoy, and it is likely that seas of 7 feet or greater will continue to impact the deep Gulf waters and Lower Straits through the rest of the night. For the late evening forecast issuance, will drop the Small Craft Advisory (SCA) for the nearshore Gulf waters and western Hawk Channel, but continue the SCA (Small Craft Advisory) for the waters further offshore still impacted by the large seas. Small Craft Exercise Caution headlines will remain posted through the night for all waters not included in the SCA.

Climate
The high temperature at Key West today managed to reach 80 degrees during a sunny period in the afternoon. This extends the record streak during which the high at Key West reached at least 80 degrees to 234 days. The last day on which the high remained below 80 degrees was March 27, when the high temperature was 78. We do expect the streak to finally end on Sunday, when all available model guidance shows Key West reaching only the mid to upper 70s.

NOAA Key West FL Office: Watches - Warnings - Advisories
FL...None. GM...Small Craft Advisory for GMZ033-034-054-055-074-075.